{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T18:56:23Z","timestamp":1792090583045,"version":"4.4.0"},"reference-count":51,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2025,3,4]],"date-time":"2025-03-04T00:00:00Z","timestamp":1741046400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Australian National Health and Medical Research Council","award":["NHMRC GNT2019988"],"award-info":[{"award-number":["NHMRC GNT2019988"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background: The BCG vaccine has long been hypothesised to have non-specific protective effects, and early epidemiological studies on COVID-19 suggested a possible protective effect against SARS-CoV-2 infection and COVID-19 severity. This systematic review and meta-analysis assesses the effect of the BCG vaccine on preventing severe COVID-19 disease, based on the rate of hospitalisation for COVID-19 related disease. Methods: We performed a literature search of randomised control trials comparing BCG vaccine to placebo in adult participants using EMBASE, MEDLINE, and Web of Science. A random effects model was used to generate summary estimates. Risk of bias was assessed regarding randomisation, allocation sequence concealment, blinding, incomplete outcome data, selective outcome reporting, and other biases. Results: We included 11 studies involving 18,412 participants, reporting COVID-19 incidence. The hospitalisation rate was sought from the authors of papers that did not report on this statistic. There was no significant reduction in COVID-19-related hospitalisation across all studies (relative risk 0.85, 0.51\u20131.40, p = 0.335), COVID-19 incidence across all studies (relative risk 1.07, 0.94\u20131.21, p = 0.264), deaths reported in six studies (relative risk 0.67, 0.36\u20131.26, p = 0.733), and COVID-19-related critical care admissions reported in four studies (relative risk 0.43, 0.13\u20131.46, p = 0.746). Conclusions: The findings from this meta-analysis, involving a large number of participants, suggest no protective effect of BCG vaccination against severe COVID-19 outcomes or overall SARS-CoV-2 incidence. Further research may be needed to explore the potential non-specific effects of BCG vaccination in other specific populations and against other infections.<\/jats:p>","DOI":"10.3390\/vaccines13030267","type":"journal-article","created":{"date-parts":[[2025,3,4]],"date-time":"2025-03-04T03:26:21Z","timestamp":1741058781000},"page":"267","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Efficacy of Bacille Calmette\u2013Gu\u00e9rin Against COVID-19 Hospitalisation: A Meta-Analysis and Systematic Review of Randomised Control Trials"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-5888-2552","authenticated-orcid":false,"given":"Joseph","family":"Inauen","sequence":"first","affiliation":[{"name":"Royal Adelaide Hospital, Port Road, Adelaide, SA 5000, Australia"},{"name":"Faculty of Health and Medical Sciences, University of Adelaide, North Terrace, Adelaide, SA 5000, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sam","family":"LaBroome","sequence":"additional","affiliation":[{"name":"Royal Adelaide Hospital, Port Road, Adelaide, SA 5000, Australia"},{"name":"Faculty of Health and Medical Sciences, University of Adelaide, North Terrace, Adelaide, SA 5000, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonietta","family":"Maldari","sequence":"additional","affiliation":[{"name":"Royal Adelaide Hospital, Port Road, Adelaide, SA 5000, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7637-8013","authenticated-orcid":false,"given":"Natalie E.","family":"Stevens","sequence":"additional","affiliation":[{"name":"Precision Medicine Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia"},{"name":"Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3864-8518","authenticated-orcid":false,"given":"James B.","family":"Geake","sequence":"additional","affiliation":[{"name":"Royal Adelaide Hospital, Port Road, Adelaide, SA 5000, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4664-1404","authenticated-orcid":false,"given":"David J.","family":"Lynn","sequence":"additional","affiliation":[{"name":"Precision Medicine Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia"},{"name":"Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6030-321X","authenticated-orcid":false,"given":"Simone","family":"Barry","sequence":"additional","affiliation":[{"name":"Royal Adelaide Hospital, Port Road, Adelaide, SA 5000, Australia"},{"name":"Faculty of Health and Medical Sciences, University of Adelaide, North Terrace, Adelaide, SA 5000, Australia"},{"name":"Precision Medicine Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"512","DOI":"10.1016\/j.smim.2014.09.006","article-title":"BCG-induced protection: Effects on innate immune memory","volume":"26","author":"Netea","year":"2014","journal-title":"Semin. 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